•350 Pari III. — Tirenfieth Annual Report 



The fourth series contained 336 females and 310 males, the former 

 ranging from 263 to 361 mm., with a mean size of 316*2 mm,, or 12^\^^ 

 inches, and the latter from 259 to 357 mm., with a mean size of 

 314"9 mm., or 12| inches. The average for the curve-group of mixed 

 sexes (640 fishes) was 315*3 mm., or 12| inches. 



The fifth series comprised 220 females, from 363 to 442 mm., 

 with an average size of 400"3 mm., or 15| inches, and 150 males, 

 ranging from 358 to 405 mm., and having a mean length of 

 375'9 mm., or 14j-;| inches. The mean size for the curve-group 

 comprising 392 fishes of both sexes was 39r6 mm., or ISJ^j- inches. 



The sixth series contained forty -six females, from 444 to 479 mm., 

 the average size being 459*7 mm., or 18^ inches, and eighteen males, 

 from 411 to 446 mm., and an average length of 425*0 mm., or 16f 

 inches. The mean for this part of the curve, comprising 48 fishes, 

 was 459*4 mm., or 18g inches. 



There were thirteen females and one male larger, of which eleven 

 females, from 490 to 540 mm., and a mean size of 507*4 mm. (19J-|- 

 inches), and the male, measuring 460 mm., appear to form one group. 

 The remaining two females were 572 and 587 mm. respectively, with an 

 average of 579*5 mm., or 22^ inches, and they seem to represent 

 another older group. 



The plaice taken in several hauls in various parts of the Moray 

 Firth were also measured, but in several cases the curves based upon 

 them were so irregular that that they had to be discarded, and the 

 sexes were usually not determined. 



In a haul in the Dornoch Firth on 11th October 1900, in from 

 eight to twelve fathoms, the measurements of 334 plaice were 

 grouped as follows : — 



The youngest series, comprising eighty fishes, ranged from 1 43 to 

 196 mm., and had an average size of 170*6 mm. The second series, 

 of 165 fishes, varied from 200 to 278 mm., with an average length of 

 240*1 mm. The third, comprising thirty-six fishes, had a mean size of 

 314*2 mm., and a range from 287 to 350 mm. The fourth, containing 

 forty-one fishes from 360 to 420 mm., had a mean length of 

 383*4 mm. There were twelve larger plaice, of which seven varied 

 from 433 to 494 mm., and had an average size of 458*4 mm. The 

 other five, measuring 544, 578, 578, 660, and 679 mm., belonged 

 probably to three groups. 



On 5th and 7th November the plaice got in a haul in the same 

 locality were measured. The first series was composed of seven plaice 

 from 76 to 88 mm., and with an average size of 82*7 mm. The second 

 series, comprising 126 plaice from 132 to 201 mm., had an average 

 size of 171*4 mm., or 6f inches. The third series included 266, 

 measuring from 204 to 282 mm., and with a mean size of 2491 mm., 

 or 9i|^ inches. The fourth series, containing 211 plaice from 283 

 to 349 mm., had an average size of 313*9 mm., or 12|^ inches; a 

 fifth series, comprising 121 fishes from 350 to 403 mm., had an 

 average of 373*5 mm., or 14^1 inches. 



Another series of thirty-six, from 405 to 452 mm., appeared to form 

 a group with an average of 421*6 mm. There were other thirteen 

 plaice, measuring from 470 to 675 mm., difficult to group, but 

 obviously forming several series. Their measurements were 470, 472, 

 and 493 mm. ; 527 and 529 mm. ; 560 and 562 mm. ; 587, 600, and 

 609 mm, ; 632 and 633 mm., and 675 mm. If considered series as 

 grouped — and it will be observed they often occur in pairs — there 

 would be other six series with averages of 478*3, 528, 561, 598*7, 

 632*5, and 675 mm. 



